This invention relates to an oil burner such as an oil-fired space heater, and more particularly to an oil burner of the type that combustion gas produced by combustion in the oil burner and heated air are guided toward a front opening of a housing of the oil burner.
There has been widely known and used an oil burner which includes a combustion cylinder structure and a rear reflection plate and is adapted to outward discharge, through a front opening of the oil burner, heat rays emitted from the combustion cylinder structure and guide heated air and combustion gas to the front opening of the oil burner. The oil burner is provided therein with a guide plate, which is generally arranged above the combustion cylinder structure. Unfortunately, such arrangement of the guide plate causes a portion of the guide plate right above the combustion cylinder structure to be locally heated, so that a portion of a top plate of a housing positioned above a central portion of the front opening is particularly heated to an elevated temperature. In order to avoid the problem, it is attempted that a front end of the cover plate is downward bent or provided with a fin for varying an angle of discharge of combustion gas, to thereby forward direct the flow of combustion gas, and render the temperature distribution to the guide plate and top plate substantially uniform, as disclosed in Japanese Utility Model Publication No. 15885/1975.
Recently, the down-sizing and high calorie outputting of an oil burner has been well in progress, therefore, it is highly desired to eliminate the above-described local heating of the top plate and guide plate. For example, the UL safety standard in the United states defines a doping test requiring that when combustion takes place in an oil burner while covering the oil burner with gauze-like cloth, the cloth fails to ignite within 30 seconds from the start of combustion. Also, the Japanese Industrial Standard (JIS) defines a wind-resistance test which requires that a combustion flame fails to get out of an oil burner when wind of a predetermined velocity is caused to blow against the oil burner. The doping test and wind-resistance test are generally unfavorable to a down-sized oil burner.